Certain beverage preparation machines use capsules containing ingredients to be extracted or to be dissolved and/or ingredients that are stored and dosed automatically in the machine or else are added at the time of preparation of the drink. Some beverage machines possess filling means that include a pump for liquid, usually water, which pumps the liquid from a source of water that is cold or indeed heated through heating means.
Especially in the field of coffee preparation, machines have been widely developed in which a capsule containing beverage ingredients is inserted in a brewing unit. The brewing unit is tightly closed about the capsule, water is injected at the first face of the capsule, the beverage is produced in the confined volume of the capsule and a brewed beverage can be drained from a second face of the capsule and collected into a receptacle such as a cup or glass.
Brewing units have been developed to facilitate insertion of a capsule and removal of the capsule upon use.
EP1757 212B1 relates to an example of these brewing units. The devices comprise a frame, a fixed enclosing part for the capsule, a movable enclosing part which is mounted relative to the frame in a sliding relationship, one or two knuckle joint mechanisms that provide a mechanical system which enables to close in a steady and fluid-tight manner the enclosing parts about the capsule while also resisting to the counter-force acting while re-opening and generated by the internal brewing pressure, and a handle for directly levering the knuckle joint mechanism. Such a device forms a simple assembly enabling insertion of the capsule by vertical (gravity) fall through a passage in the frame and removal of the used capsule in the same direction as the insertion direction. The movable enclosing parts of the brewing unit are actuated manually via the handle.
An important aspect is to provide a unit which is convenient and reliable for insertion of a capsule in the passage followed by closure of the brewing unit around the capsule and, after brewing, ejection of the capsule from unit.
In EP1757212B1, the device comprises stop means such as pivoting guiding jaws which the second mobile part acts on in order to move them apart during the passage of the capsule from its intermediate position to its position of extraction. In particular, the jaws are moved apart by lateral actuation levers which act on tabs of the guiding jaws so as to move them from a capsule holding position to a capsule release position and vice versa. The lateral actuating levers are mounted along vertical pivot axes to be able to swivel when any one of their two opposite free ends is engaged by a protruding cams positioned on the side of the moving enclosing part.
WO2011/151781A1 relates to a brewing apparatus for a machine for preparing beverages comprising a capsule gripping device including a pair of movable jaws and telescopic pushers provided with respective transversely protruding parting formations having respective first and second pushing surfaces capable of parting the jaws when the movable receiving assembly moves towards and away from the closed position respectively.
EP2520203B1 relates to an apparatus for preparing a beverage started from a powder material contained in a sealed cartridge, comprising a percolating assembly and a cartridge loading and unloading device including a pair of jaws adapted to held the cartridge at an infusion position and to discharge the cartridge at the end of the infusion to provide the space for a new cartridge; said jaws being driven from an unloading spread apart position to a cartridge restraining closed position by telescopic cams associated with the percolating assembly.
WO2012085774A1 relates to an infusion apparatus for a machine for preparing beverages comprising a movable assembly and a cooperating assembly adapted to define an infusion chamber, a gripper type holding device including a pair of movable jaws adapted to assume a relative holding position in which the jaws are capable of receiving and retaining a capsule introduced between the assemblies; and opening means opening the jaws; said opening means comprising a bearing structure and a spring-biased opening member capable of maintaining the gripper type holding device with jaws wide open for a predetermined stroke of the movable assembly which is adapted to allow the exhausted capsule to be released.
The prior art essentially discloses loading and unloading jaw-type systems in which the actuation requires either a telescopic or a movable additional actuation means (e.g., swiveling actuation levers). The problem lies in the complexity and the risk of blocking of these devices.
Another problem lies in the lack of precise control of the positioning or centering of the capsule relative to the enclosing members during the closure of the brewing unit. Indeed, for example, if the two telescopic or movable members are not perfectly coordinated, one of the two jaws may release the capsule sooner thereby causing the capsule to position itself in a biased arrangement in the receiving cavity of the capsule enclosing assembly. Considering the capsule enclosing assembly can be a rotational or centrifugal system driving the capsule at high elevated speeds, a lack of centering of the capsule in the enclosing assembly may cause damage to the capsule and/or unbalance of the rotational extraction system which may create vibrations and/or noises.